低温裂解水稻秸秆生物炭对水体中Pb/Cd吸附的应用研究  

Application of Low Temperature Pyrolysis Rice Straw Biochar in Pb/Cd Absorption from Water

作　　者：杨海征 袁宗琪 徐晓林 王建玲 YANG Haizheng;YUAN Zongqi;XU Xiaolin;WANG Jianling(School of Chemistry and Environmental Science,Qujing Normal University,Qujing Yunnan 655011;Yunnan University Collaborative Innovation Center,Qujing Yunnan 655011,China)

机构地区：[1]曲靖师范学院化学与环境科学学院,云南曲靖655011 [2]云南省高校协同创新中心(曲靖绿色光伏产业协同创新中心),云南曲靖655011

出　　处：《曲靖师范学院学报》2024年第3期13-23,共11页Journal of Qujing Normal University

基　　金：云南省科技厅科技人才与平台计划“云南省李和兴专家工作站”(202305AF150088);云南省教育厅科学研究基金项目“基于秸秆基生物复合材料对Pb/Cd污染红壤修复的研究”(2021J0502).

摘　　要：为寻找一种来源丰富、价格低廉、经济有效的生物炭治理水体中Pb/Cd污染,在限氧条件下将粉碎的水稻秸秆(RY)400℃热裂解30 min制备了水稻秸秆生物炭(RS).本研究对RS进行了表征,研究了RY及RS对溶液中Pb^(2+)/Cd^(2+)的吸附特性.结果表明:RS具有丰富的官能团,表面具有明显的孔隙结构.RS吸附Pb^(2+)的最佳条件为:在室温条件下,pH在6.0~8.0之间,固液比为1.0 g·L-1;生物炭吸附Cd^(2+)的最佳条件为:在25℃条件下,pH在7.0附近,固液比为10.0 g·L-1.吸附动力学实验分析发现,RS对Pb^(2+)、Cd^(2+)的吸附率远远高于RY对Pb^(2+)、Cd^(2+)的吸附率,在35 min时RS对Pb^(2+)的吸附已经基本达到平衡,在40 min时RS对Cd^(2+)的吸附已经达到平衡.等温吸附实验分析发现,RS对溶液中Pb^(2+)的等温吸附更符合Freundlich等温吸附模型,主要为多层吸附;生物炭对溶液中Cd^(2+)的等温吸附过程更符合Langmuir等温吸附模型,主要为单层吸附.研究表明,利用廉价丰富的水稻秸秆材料在低温少时条件下制备生物炭来治理水体中Pb/Cd污染是可行的,本研究以期为重金属环境污染治理提供经济有效的方法.Rice straw biochar(RS)was prepared by thermal cracking of crushed rice straw(RY)400℃for 30min under oxygen restriction in order to find a rich,inexpensive and cost-effective biochar to control Pb/Cd pollution in water.The RS characteristics and the absorption behavior of RS to Pb^(2+)/Cd^(2+)in solution were investigated.The results showed that RS was full of abundant functional groups and obvious pore structures on its surface.The best condition for RS absorption of Pb^(2+)was as follows:the temperature was 25℃;pH was between 6.0 and 8.0;and solid-liquid ratio was 1.0g·L-1.Meanwhile,the optimum condition for biochar absorption of Cd^(2+)was as follows:the temperature was at 25℃;pH was near 7.0;and solid-liquid ratio was 10.0g·L-1.The analysis of absorption kinetics showed that the adsorption rate of Pb^(2+)and Cd^(2+)by RS was much higher than that of Pb^(2+)and Cd^(2+)by RY.The absorption rate of Pb^(2+)by RS reached a basic equilibrium at 35min,and the absorption rate of Cd^(2+)by RS reached an equilibrium at 40min,which indicated that the isothermal absorption of Pb^(2+)by RS is more consistent with Freundlich isothermal absorption model being mainly multi-layer adsorption.The isothermal absorption process of Cd^(2+)in solution by biochar is more consistent with Langmuir isothermal adsorption model,which is mainly monolayer absorption.The study shows that it is feasible to to prepare biochar from cheap and abundant rice straw materials at low temperature to control Pb/Cd pollution in water,which could provide an economical and effective method for heavy metal environmental pollution control.

关 键 词：水稻秸秆生物炭 低温裂解 铅吸附 镉吸附 

分 类 号：O69[理学—化学] X712[环境科学与工程—环境工程]